WO2022202654A1

WO2022202654A1 - Magnetic modulation gear device, drive device, and robot

Info

Publication number: WO2022202654A1
Application number: PCT/JP2022/012566
Authority: WO
Inventors: 泰三山本; 貴浩三成; 博貴中川
Original assignee: 住友重機械工業株式会社
Priority date: 2021-03-26
Filing date: 2022-03-18
Publication date: 2022-09-29
Also published as: EP4318897A4; JP2022150614A; EP4318897A1; CN117044084A

Abstract

To address the problem of eliminating the need for a torque sensor, a magnetic modulation gear device 30 is configured to include: an input shaft 23; an output shaft 32b the speed of which is changed relative to the input shaft 23 by way of a speed reducing unit and is output; an input shaft-side sensor 35 which measures an angle of rotation on the input shaft 23 side; and an output shaft-side sensor 36 which measures an angle of rotation on the output shaft 32b side.　For example, a drive device 1 is provided with the magnetic modulation gear device 30, a drive source 20 which inputs torque to the input shaft, and a control device 40 which controls an operating amount of the drive source on the basis of the measured angle of rotation on the input shaft side and the measured angle of rotation on the output shaft side such that a target torque is achieved, thereby controlling the torque on the output shaft side without employing a torque sensor.

Description

Magnetic modulation gear system, drive system and robot

The present invention relates to a magnetic modulation gear device, a drive device and a robot.

Conventionally, a magnetic modulation gear device is known in which a magnetic pole piece member having a plurality of magnetic pole pieces is arranged between two magnets arranged on the inner and outer circumferences to modulate the magnetic flux distribution between the inner and outer circumference magnets. In this magnetic modulation gear device, torque is transmitted between magnets on the inner peripheral side and the magnetic pole piece members thereof to transmit deceleration or acceleration rotation (see, for example, Patent Document 1).

JP 2017-17984 A

　Conventional magnetic modulation gear devices were required to control the transmitted torque.

The present invention has been made in view of the above circumstances, and an object of the present invention is to be able to suitably perform torque control.

The present invention provides a magnetic modulation gear device,
In a magnetic modulation gear device having an input shaft and an output shaft that is output after being speed-changed with respect to the input shaft through a reduction section,
an input shaft side sensor that measures the rotation angle of the input shaft side;
and an output shaft side sensor for measuring the rotation angle of the output shaft side.

Further, the present invention provides a driving device,
the magnetic modulation gear device;
a drive source that inputs torque to the input shaft;
A torque estimator for estimating the torque transmitted from the input shaft to the output shaft from the rotation angle measured by the input shaft side sensor and the rotation angle measured by the output shaft side sensor. and a control device for controlling the torque of the power source.

Further, the present invention provides a driving device,
the magnetic modulation gear device;
a drive source that inputs torque to the input shaft;
a control device that controls the operation amount of the drive source so as to achieve a target torque based on the measured rotation angle of the input shaft and the measured rotation angle of the output shaft.

In addition, according to the present invention, the robot is configured to have the driving device described above.

According to the present invention, torque control can be handled without providing a dedicated torque sensor.

1 is an axial cross-sectional view of a drive device according to a first embodiment; FIG. 1 is a perspective view of a magnetically modulated gear device; FIG. FIG. 4 is a diagram showing the relationship between the phase difference and the output torque on the output shaft; It is an axial sectional view of the drive device which concerns on 2nd Embodiment. It is an axial sectional view of the drive device concerning 3rd Embodiment. It is a side view of the robot to which the drive is applied.

[First embodiment]
A first embodiment of the present invention will be described in detail below with reference to the drawings.
FIG. 1 is an axial cross-sectional view of the drive device 1 according to the first embodiment.
As shown in this figure, the driving device 1 according to this embodiment includes a motor 20 , a magnetic modulation gear device 30 , and a control device 40 that controls the torque of the driving device 1 .

[motor]
The motor 20 exemplifies a motor capable of controlling the amount of rotation angle, such as a brushless motor.
The motor 20 has a motor rotor and a motor stator (both not shown), and the motor rotor has a shaft 23, a rotor yoke 31b, and an inner pole magnet (rotor magnet) 31a. The rotor yoke 31b is made of a magnetic material and provided on the outer peripheral surface of the shaft 23, and the inner pole magnet 31a is provided on the outer peripheral surface of the rotor yoke 31b.
The motor stator is composed of a stator core wound with a plurality of coils, and the motor rotor (shaft 23) is rotationally driven by energizing the plurality of coils in a predetermined order.
Further, the shaft 23 extends inside the magnetic modulation gear device 30 .
In the following description, the direction along the central axis Ax of the shaft 23 is "axial direction", the direction perpendicular to the central axis Ax is "radial direction", and the direction of rotation about the central axis Ax is "circumferential direction". It says. Further, in the axial direction, the side where the output shaft 32b of the driving device 1 is connected to an external driven member (the left side in the drawing) is referred to as the "load side", and the opposite side to the load side (the right side in the drawing). ) is called the “anti-load side”.

[Magnetic Modulation Gear Device]
The magnetic modulation gear device 30 is arranged on the load side of the motor 20 and functions as a transmission (for example, a reduction gear) that changes the speed of rotation input from the motor 20 and outputs it to the load side. The magnetic modulation gear device 30 and the motor 20 share the shaft 23 . In other words, the shaft 23 functions as an input shaft of the magnetic modulation gear device 30 .
Specifically, the magnetic modulation gear device 30 includes a high-speed rotor 31, a low-speed rotor 32, an outer pole magnet 33, a casing 34 as a housing, and an input shaft side sensor that measures the rotation angle of the shaft 23 side. Equipped with a high-speed shaft rotation angle sensor 35, a low-speed shaft rotation angle sensor 36 as an output shaft side sensor that measures the rotation angle of the output shaft 32b, and a temperature sensor 37 that detects the temperature of the magnet of the magnetic modulation gear device 30. .

As shown in FIG. 1 , the casing 34 is a cylindrical body concentric with the shaft 23 , and the shaft 23 of the motor 20 passes through the center of the casing 34 to close the non-load side end of the casing 34 . It extends from the cover 11 to the inside of the hollow output shaft 32b provided in the load-side cover 13 that closes the load-side end of the casing 34. As shown in FIG.
The shaft 23 is rotated around the central axis Ax by a bearing 12a (for example, a ball bearing) provided at the center of the anti-load side cover 11 and a bearing 12b (for example, a ball bearing) provided on the inner circumference of the output shaft 32b. rotatably supported.

The output shaft 32 b is arranged concentrically with the shaft 23 on the load side of the shaft 23 . The output shaft 32b includes a solid shaft portion 321b, a hollow cylindrical portion 322b provided at the non-load side end of the shaft portion 321b, and a hollow cylindrical portion 322b provided at the non-load side end of the cylindrical portion 322b. and a flange portion 323b. The shaft portion 321b, the cylindrical portion 322b, and the flange portion 323b of the output shaft 32b are integrated and arranged concentrically with the shaft .
The outer circumference of the cylindrical portion 322b is rotatably supported by a bearing 32f (for example, a ball bearing) provided at the center of the load side cover 13. As shown in FIG. Furthermore, the non-load-side end of the cylindrical portion 322b opens toward the non-load side, and rotatably supports the shaft 23 by the bearing 12b on the inner peripheral portion.
Note that the output shaft 32b does not have to be hollow as long as it has a structure in which the load-side end of the shaft 23 is not supported inside the output shaft 32b. Alternatively, the load side (not shown) of the output shaft 32b may be a solid shaft. That is, the shape of the output shaft is not particularly limited.

FIG. 2 is a perspective view of the magnetic modulation gear device 30. FIG.
As shown in FIGS. 1 and 2, the high-speed rotor 31 includes a shaft 23, a rotor yoke 31b, and inner pole magnets 31a. The rotor yoke 31b is fixedly attached to the outer circumference of the shaft 23 in the casing 34 at a position approximately in the middle in the axial direction (strictly speaking, somewhat closer to the anti-load side). The rotor yoke 31b has a uniform outer diameter over the entire length in the axial direction, and the inner pole magnet 31a is fixedly attached to the outer periphery. The inner pole magnet 31a also has a uniform outer diameter over the entire length in the axial direction.

The inner pole magnet 31a is, for example, a permanent magnet such as a neodymium magnet, and a plurality of magnets having opposite polarities are attached alternately along the circumferential direction to the outer peripheral surface of the rotor yoke 31b. The inner pole magnet 31a forms a magnetic pole consisting of a plurality of pole pairs. Also, instead of the plurality of inner pole magnets 31a, an integral ring-shaped magnet may be used.

The low-speed rotor 32 has the aforementioned output shaft 32b and a plurality of magnetic pole pieces (pole pieces) 32a.
The plurality of magnetic pole pieces 32 a are arranged concentrically with the high-speed rotor 31 so as to surround the high-speed rotor 31 .
The plurality of magnetic pole pieces 32a are formed from laminated steel plates and arranged at predetermined intervals in the circumferential direction. Any soft magnetic material may be used for the magnetic pole piece 32a. For example, dust core, amorphous, SPCC, etc. may be used. The number of magnetic pole pieces 32a is the number of outer pole pairs (the number of pole pairs of outer pole magnet 33)±the number of inner pole pairs (the number of pole pairs of inner pole magnet 31a), generally the number of outer pole pairs+the number of inner pole pairs. Two magnetic pole pieces 32a adjacent to each other in the circumferential direction may be connected by a thin connecting portion, or may be connected by a non-magnetic material.

A resin portion 32c is fixed to both ends of the magnetic pole piece 32a in the axial direction, and a flange portion 323b of the output shaft 32b is fixed to the resin portion 32c on the load side with a bolt 32d (for example, made of resin such as super engineering plastic). It is Note that the connection method is not limited even if it is not the connection by the bolt 32d. For example, the resin portion 32c and the output shaft 32b may be integrally molded. As described above, the output shaft 32b has the load-side shaft portion 321b exposed from the casing 34 and connected to a driven member (not shown).
The low-speed rotor 32 is rotatably supported by the casing 34 via a bearing 32e provided on the non-load side of the magnetic pole piece 32a and a bearing 32f supporting the output shaft 32b. Of these, the anti-load side bearing 32e is disposed between the casing 34 and a ring member 32g made of stainless steel fixed to the anti-load side resin portion 32c of the magnetic pole piece 32a. The load-side bearing 32f is arranged between the load-side cover 13 of the casing 34 and the cylindrical portion 322b of the output shaft 32b, as described above.

The outer pole magnets 33 are arranged concentrically on the outer periphery of the plurality of magnetic pole pieces 32a with a predetermined gap therebetween. The number of pole pairs of the outer pole magnets 33 is larger than that of the inner pole magnets 31a of the high-speed rotor 31, and a plurality of the outer pole magnets 33 having opposite polarities are alternately arranged in the circumferential direction. These outer pole magnets 33 are attached to the inner peripheral surface of the yoke portion 33a fitted inside the casing 34 in the above arrangement, and function as a stator. Further, instead of the plurality of outer pole magnets 33, an integral ring-shaped magnet may be used.
The inner pole magnet 31a, the magnetic pole piece 32a, and the outer pole magnet 33 described above constitute a reduction section provided between the input shaft and the output shaft.

The high-speed shaft rotation angle sensor 35 has a detected portion 351 that rotates integrally with the shaft 23 and a sensor portion 352 that is arranged near the detected portion 351 and detects the detected portion 351 .
The low-speed shaft rotation angle sensor 36 has a detected portion 361 that rotates integrally with the output shaft 32 b and a sensor portion 362 that is arranged near the detected portion 361 and detects the detected portion 361 .
The high-speed shaft rotation angle sensor 35 and the low-speed shaft rotation angle sensor 36 are arranged in the same space inside the casing 34 .

The high-speed shaft rotation angle sensor 35 and the low-speed shaft rotation angle sensor 36 are, for example, rotary encoders that output the rotational displacement of the shaft 23 and the output shaft 32b as digital signals, but a resolver that outputs analog signals can also be used. Alternatively, other rotation detectors may be used. The rotary encoder may be configured to have an optical detection section, or may be configured to have a magnetic detection section. Further, the high-speed shaft rotation angle sensor 35 and the low-speed shaft rotation angle sensor 36 may be different types of detectors.

A detected portion 351 of the high-speed shaft rotation angle sensor 35 is composed of a disc (or ring) fixedly mounted on the shaft 23 at a position facing the load-side surface of the anti-load-side cover 11 . The detected portion 351 is provided concentrically with the shaft 23 and rotates together with the shaft 23 around the central axis Ax.
The detected portion 351 has, for example, a code that can be read optically or magnetically from the anti-load side along the circumference centered on the central axis Ax on the surface on the anti-load side. Moreover, when forming the detected part 351 in a ring shape, these codes may be formed on the outer circumference or the inner circumference of the ring.

The sensor section 352 is fixedly mounted on the load-side surface of the non-load-side cover 11 of the casing 34 . The sensor section 352 is arranged so as to face the detected section 351 in close proximity. The sensor section 352 is composed of, for example, an optical sensor or a magnetic sensor capable of reading the code of the detected section 351 .

A detected portion 361 of the low-speed shaft rotation angle sensor 36 is composed of a disk (or ring) fixedly mounted on the outer circumference of the flange portion 323b of the output shaft 32b. The detected portion 361 is provided concentrically with the output shaft 32b, and rotates around the central axis Ax together with the output shaft 32b.
The detected portion 361 has, for example, an optically or magnetically readable code formed on the load-side surface along the circumference around the central axis Ax. Moreover, when forming the detected part 361 in a ring shape, these codes may be formed on the outer circumference or the inner circumference of the ring.

The sensor section 362 is fixedly mounted on the inner periphery of the casing 34 near the load side of the flange section 323b of the output shaft 32b. The sensor portion 362 is arranged to extend radially inward so as to face the detected portion 361 in close proximity. The sensor section 362 is composed of, for example, an optical sensor or a magnetic sensor capable of reading the code of the detected section 361 .

In the above example, the detected

portions

351 and 361 of the high-speed shaft rotation angle sensor 35 and the low-speed shaft rotation angle sensor 36 and the

sensor portions

352 and 362 face each other in the axial direction. and non-detection portions are not limited. For example, when the cords of the detected

portions

351 and 361 are formed on the outer circumference or the inner circumference of the ring, the

sensor portions

352 and 362 are arranged radially outside or inside the detected

portions

351 and 361, The

detection units

351 and 361 and the

sensor units

352 and 362 may be arranged to face each other in the radial direction.

The temperature sensor 37 detects the temperature of the outer pole magnet 33 as a magnet. This temperature sensor 37 is attached to the outer pole magnet 33 . As the temperature sensor 37, a thermocouple, a resistance temperature detector, a thermistor, or other sensor capable of contacting and detecting a temperature to be measured can be used. For example, a non-contact sensor, such as an infrared detector, which can detect the temperature from a position distant from the object to be detected may be used.

[Control device]
In the driving device 1, input torque is applied to the shaft 23 when the motor 20 is driven. As a result, the high-speed rotor 31 of the magnetic modulation gear unit 30 rotates together with the shaft 23, and the spatial magnetic flux waveform of the inner pole magnet 31a of the high-speed rotor 31 is frequency-modulated by the magnetic pole pieces 32a of the low-speed rotor 32, Torque is transmitted. At this time, the reduction ratio is (the number of magnetic poles of the magnetic pole pieces 32a of the low-speed rotor 32)/(the number of pole pairs of the inner pole magnets 31a).

FIG. 3 is a diagram showing the relationship between the phase difference and the output torque on the output shaft 32b.
As described above, the magnetic modulation gear device 30 rotates the magnetic pole pieces at a speed reduction ratio determined by (the number of magnetic poles of the magnetic pole pieces 32a of the low-speed rotor 32)/(the number of pole pairs of the inner pole magnets 31a) with respect to the rotation angle of the shaft 23. 32a and output shaft 32b rotate. At this time, when the rotation angle of the output shaft 32b when the output shaft 32b rotates at the rotation angle corresponding to the reduction ratio with respect to the rotation of the shaft 23 is taken as a reference position, the following is obtained with respect to the reference position of the output shaft 32b When a phase difference occurs due to a delay in the rotation angle of the output shaft 32b, an output torque is generated in the output shaft 32b. The output torque generated on the output shaft 32b has a correlation with the phase difference as shown in FIG. 3, for example.
In the example of FIG. 3, the period of one magnetic pole piece 32a is 360 [deg], and the output torque of the output shaft 32b is 0 when the phase difference generated in the output shaft 32b is 0 or ±180 [deg]. , the output torque is maximized when the phase difference is ±90[deg].

The control device 40 executes torque control based on the characteristics of the phase difference generated in the output shaft 32b and the output torque of the output shaft 32b.
Specifically, as shown in FIG. 1, the control device 40 controls the target position of the output shaft 32b for outputting the target output torque in response to the torque command T ^* indicating the target output torque to be generated in the output shaft 32b. A phase difference output unit 41 that outputs the phase difference θ ^* , a phase difference calculation unit 42 that calculates the phase difference θ_fb currently occurring on the output shaft 32b, and a target phase difference θ ^* and the current phase difference occurring on the output shaft 32b. and a subtractor 43 for obtaining a deviation θ_cmd from the phase difference θ_fb.
Each of the above configurations of the control device 40 may be implemented by hardware, or the control device 40 may be configured from an arithmetic processing device and functionally implemented by software processing.

The phase difference output unit 41 stores table data based on the characteristics (for example, the characteristics of FIG. 3) between the phase difference generated in the output shaft 32b of the low-speed rotor 32 and the output torque generated in the output shaft 32b. The table data defines the target phase difference θ ^* of the output shaft 32b corresponding to each of a plurality of numerical values of the torque command T ^* (target output torque) ^. is input, the target phase difference θ ^* of the corresponding output shaft 32b defined in the table data is specified and output.

In addition, different table data are prepared for each of a plurality of rotation angles of the shaft 23 .
Further, the table data for each rotation angle of the shaft 23 is prepared for a plurality of different temperatures by correcting each target phase difference θ ^* value in consideration of the influence of the surrounding environmental temperature. .
Therefore, the phase difference output unit 41 selects appropriate table data based on the rotation angle of the shaft 23 detected by the sensor unit 352 of the high-speed shaft rotation angle sensor 35 and the temperature detected by the temperature sensor 37, and Specify and output the target phase difference θ ^* .

The phase difference calculator 42 receives the rotation angle of the shaft 23 detected by the sensor section 352 of the high-speed shaft rotation angle sensor 35 and the rotation angle of the output shaft 32b detected by the sensor section 362 of the low-speed shaft rotation angle sensor 36. be done.
The phase difference calculator 42 calculates the rotation angle (phase) of the output shaft 32b from the detected rotation angle (phase) of the shaft 23 when the output shaft 32b rotates at the rotation angle corresponding to the speed reduction ratio set in the magnetic modulation gear device 30. An angle (phase) is obtained as a reference position. Further, the difference between the reference position and the rotation angle (phase) of the output shaft 32b detected by the low-speed shaft rotation angle sensor 36 is obtained to calculate the phase difference θ_fb occurring in the output shaft 32b.

The subtractor 43 outputs the target phase difference θ ^* of the output shaft 32b for obtaining the torque command T ^* (target output torque) output from the phase difference output unit 41, and the output from the phase difference calculation unit 42 is The phase difference θ_fb actually occurring on the output shaft 32b is subtracted to calculate the phase difference deviation θ_cmd of the output shaft 32b.
Further, the deviation θ_cmd of the phase difference is multiplied by a predetermined gain, and the multiplied value is input as the operation amount of the motor 20 .
As a result, the amount of motion input from the motor 20 to the shaft 23 is controlled so that the target phase difference θ ^* is generated on the output shaft 32b, and the target output torque corresponding to the torque command T ^* is generated on the output shaft 32b.

[Technical effect of the first embodiment]
Since the magnetic modulation gear device 30 of the drive device 1 has a high-speed shaft rotation angle sensor 35 for measuring the rotation angle of the shaft 23 and a low-speed shaft rotation angle sensor 36 for measuring the rotation angle of the output shaft 32b, The phase difference generated in the output shaft 32b can be easily obtained from the outputs of these

sensors

35 and 36, and the output torque of the output shaft 32b can be easily controlled based on the phase difference. torque control can be performed.
As a result, the driving device 1 can easily control the output torque without providing a dedicated torque sensor for detecting torque, simplifying the configuration of the device, reducing the number of parts, and furthermore , it is possible to reduce the size of the device and the manufacturing cost.

In addition, the driving device 1 has a high-speed shaft rotation angle sensor 35 and a low-speed shaft rotation angle sensor 36 arranged in the casing 34 of the magnetic modulation gear device 30 . Since the magnetic modulation gear device 30 does not require lubricating oil in the casing 34 unlike a speed reducer or the like that utilizes meshing of gears, the

sensors

35 and 36 can be arranged in a clean environment. Furthermore, since the casing 34 protects the

sensors

35 and 36 from contact with the outside, shock absorption, adhesion of dust and the like, the

sensors

35 and 36 can perform stable detection over a long period of time, and the system can be Reliability can be improved.

Further, the driving device 1 detects the rotation angle of the shaft 23 detected by the sensor portion 352 of the high-speed shaft rotation angle sensor 35 and the rotation angle of the output shaft 32b detected by the sensor portion 362 of the low-speed shaft rotation angle sensor 36. Since the controller 40 is provided for controlling the amount of operation of the motor 20 so that the target output torque determined by the torque command T ^* is output from the output shaft 32b, a torque sensor is not required, and a simple configuration can be used. It becomes possible to realize torque control of the driving device 1 .

In addition, since the control device 40 corrects the operation amount of the motor 20 to achieve the target output torque based on the temperature of the outer pole magnet 33 of the magnetic modulation gear device 30 detected by the temperature sensor 37, the influence of temperature is reflected. Therefore, the driving device 1 can perform torque control with higher accuracy.

[Second embodiment]
A second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is an axial cross-sectional view of the driving device 1A according to the second embodiment.
Regarding the driving device 1A of the second embodiment, mainly different points from the driving device 1 will be described. As shown in FIG. 4, the driving device 1A mainly differs from the driving device 1 in that it has a casing 34A as a housing common to the motor 20A and the magnetic modulation gear device 30. As shown in FIG.

As shown in FIG. 4, the casing 34A accommodates the internal construction of the motor 20A and the internal construction of the magnetic modulation gear device 30, so it is constructed of a cylindrical body that is axially longer than the casing 34 described above.
An anti-load side cover 11 and a load-side cover 13 are provided at the non-load side end and the load side end of the casing 34, respectively. It is the same as the driving device 1 in that it is rotatably supported around the central axis Ax by

bearings

12a and 12b, and the output shaft 32b is rotatably supported around the central axis Ax by a bearing 32f.

Furthermore, the motor 20A has a motor rotor 21 and a motor stator 22 . The motor rotor 21 has a shaft 23, a rotor yoke 21b, and rotor magnets 21c. The rotor yoke 21b is made of a non-magnetic material and fitted and fixed to the outer peripheral surface of the shaft 23. As shown in FIG. The rotor magnets 21c are permanent magnets such as neodymium magnets, and a plurality of magnets corresponding to a predetermined number of pole pairs are attached to a portion of the outer peripheral surface of the rotor yoke 21b located on the inner diameter side of the motor stator 22 .
The motor stator 22 is constructed by winding a coil 22b around a stator core 22a made of laminated steel plates. The stator core 22a may also be made of any soft magnetic material such as dust core, amorphous, SPCC, or the like. The motor stator 22 is arranged concentrically on the outer diameter side of the motor rotor 21, and is held by the casing 34A with the stator core 22a being fitted inside the casing 34A.

On the other hand, the magnetic modulation gear device 30 is different in that the high-speed rotor 31A uses a rotor yoke 21b common to the motor 20A instead of the rotor yoke 31b described above.
That is, the rotor yoke 21b provided on the outer circumference of the shaft 23 extends to the inside of the magnetic modulation gear device 30 provided on the load side of the motor 20A, and a plurality of rotor yokes 21b are provided on the outer circumference of the load-side end of the rotor yoke 21b. A high-speed rotor 31A of the magnetic modulation gear device 30 is configured by attaching the inner pole magnet 31a.

As for the configuration and arrangement of the low-speed shaft rotation angle sensor 36, it is arranged on the load side in the casing 34A in the same manner as the drive device 1 described above.
On the other hand, the high-speed shaft rotation angle sensor 35 is arranged on the anti-load side in the casing 34A to detect the rotation angle of the shaft 23, which is the same as the driving device 1 described above, but is arranged on the anti-load side of the motor 20A. The difference is that

The control device 40 controls the amount of movement of the motor 20A in the casing 34A, but its control configuration is the same as in the case of the drive device 1.

Therefore, also in the case of the driving device 1A, input torque is applied to the shaft 23 when the motor 20A is driven. As a result, the high-speed rotor 31A of the magnetic modulation gear device 30 rotates together with the shaft 23, and the spatial magnetic flux waveform of the inner pole magnet 31a of the high-speed rotor 31A is frequency-modulated by the magnetic pole pieces 32a of the low-speed rotor 32, Torque is transmitted. The output shaft 32b rotates at a reduction ratio of (the number of magnetic poles of the magnetic pole pieces 32a of the low-speed rotor 32)/(the number of pole pairs of the inner pole magnets 31a).

At this time, the phase difference output unit 41 of the control device 40 outputs the target phase difference θ ^* of the output shaft 32b corresponding to the torque command T ^* indicating the target output torque. On the other hand, the phase difference calculator 42 calculates the phase difference θ_fb occurring on the output shaft 32b, and the subtractor 43 calculates the phase difference deviation θ_cmd of the output shaft 32b.
Then, an operation amount determined based on the deviation θ_cmd is input to the motor 20A, and a target output torque corresponding to the torque command T ^* is generated for the output shaft 32b.

In the driving device 1A, the magnetic modulation gear device 30 and the motor 20A have a common casing 34A, and the internal structures of the magnetic modulation gear device 30 and the motor 20A are arranged in the casing 34A.
Therefore, the driving device 1A can obtain the same technical effects as the driving device 1, and can realize the downsizing and compactness of the entire device.
Further, since the internal structures of the magnetic modulation gear device 30 and the motor 20A are arranged in the same casing 34A, it becomes easy to share parts, such as sharing the rotor yoke 21b between the motor rotor 21 and the high-speed rotor 31A. It is possible to achieve simplification and a reduction in the number of parts.

[Third embodiment]
A third embodiment of the present invention will be described with reference to the drawings. FIG. 5 is an axial cross-sectional view of the driving device 1B according to the third embodiment.
Regarding the driving device 1B of the third embodiment, mainly the points different from the driving device 1A will be described. As shown in FIG. 5, the driving device 1B differs from the driving device 1A in the configuration of the control device 40B.

The control device 40B includes a phase difference calculation unit 42 that obtains the current phase difference θ_fb occurring on the output shaft 32b, and a torque acquisition unit 41B that calculates the current output torque T_fb occurring on the output shaft 32b from the phase difference θ_fb. Then, upon receiving the input of the torque command T ^* indicating the target output torque to be generated on the output shaft 32b and the current output torque T_fb generated on the output shaft 32b from the torque acquisition unit 41B, the output torque of the output shaft 32b is calculated. and a subtractor 43B for obtaining the deviation T_cmd.
It should be noted that each configuration of the control device 40B may be realized by hardware, or the control device 40B may be configured by an arithmetic processing device and functionally realized by software processing.

From the rotation angle of the shaft 23 detected by the sensor section 352 of the high-speed shaft rotation angle sensor 35 and the rotation angle of the output shaft 32b detected by the sensor section 362 of the low-speed shaft rotation angle sensor 36, the phase difference calculation section 42 calculates: A phase difference θ_fb occurring on the output shaft 32b is calculated.

The torque acquisition unit 41B stores table data based on the characteristics (for example, see FIG. 3) of the phase difference generated in the output shaft 32b of the low-speed rotor 32 and the output torque generated in the output shaft 32b.
The table data defines the value of the output torque generated on the output shaft 32b corresponding to each of a plurality of numerical values of the phase difference of the output shaft 32b. When the phase difference θ_fb generated on the output shaft 32b is input from the phase difference calculation unit 42, the torque acquisition unit 41B currently generates the corresponding torque value determined in the table data on the output shaft 32b. Output as output torque T_fb.
In other words, the phase difference calculation unit 42 and the torque acquisition unit 41B cooperate with each other to obtain the "rotation angle measured by the input shaft side sensor (high speed shaft rotation angle sensor 35) and the output shaft side sensor (low speed shaft rotation angle sensor 36). ) functions as a "torque estimator" that estimates the output torque of the output shaft 32b from the measured rotation angle.

Also, in the case of the above table data, different table data are prepared for each of a plurality of rotation angles of the shaft 23 . Furthermore, the table data for each rotation angle of the shaft 23 is prepared for a plurality of different temperatures in which table data in which each output torque T_fb value is corrected is taken into consideration the influence of the surrounding environmental temperature.
Therefore, the torque acquisition unit 41B selects appropriate table data based on the rotation angle of the shaft 23 detected by the sensor unit 352 of the high-speed shaft rotation angle sensor 35 and the temperature detected by the temperature sensor 37, and then outputs The output torque T_fb currently occurring on the shaft 32b is specified and output.

The subtractor 43B subtracts the output torque T_fb actually generated in the output shaft 32b output from the torque acquisition unit 41B from the torque command T ^* (target output torque) to obtain the deviation of the output torque of the output shaft 32b. Calculate T_cmd.
Further, the deviation T_cmd is multiplied by a predetermined gain, and torque control is performed so that the multiplied value becomes the torque that the motor 20A inputs to the magnetic modulation gear device 30 .
As a result, the torque of the motor 20A is controlled so that an appropriate phase difference is generated on the output shaft 32b, thereby generating a target output torque corresponding to the torque command T ^* on the output shaft 32b.

That is, the control device 40B, through the processing of the subtractor 43B, outputs the output torque (output torque T_fb) estimated by the phase difference calculation unit 42 and the torque acquisition unit 41B as a torque estimation unit and the target output torque (torque command T ^* ). The input torque of the drive source (motor 20A) is controlled based on the difference between .

As described above, in the drive device 1B, the output of the high-speed shaft rotation angle sensor 35 and the low-speed shaft rotation angle sensor 36 is calculated by the phase difference calculation unit 42 and the torque acquisition unit 41B in the control device 40B functioning as a torque estimation unit. It is possible to easily obtain the output torque generated on the output shaft 32b.

In addition, since the control device 40B corrects the output torque obtained by the torque obtaining section 41B based on the temperature of the outer pole magnet 33 of the magnetic modulation gear device 30 detected by the temperature sensor 37, the influence of the temperature is reflected. The driving device 1B can perform torque control with higher accuracy.

[Example of application to robots]
An application example of the driving device shown in the first to third embodiments to a robot will be described with reference to the drawings. FIG. 6 is a side view of the robot 100 as the application example.
The robot 100 includes a base 101 serving as a foundation, a plurality of arms 102 connected by joints 103, and a tool 104 held at the distal end of the plurality of connected arms 102. Each joint 103 has the above-described A drive 1 is provided.

Each of the driving devices 1 in each joint 103 of the robot 100 has a high-speed axis rotation angle sensor 35 and a low-speed axis rotation angle sensor 36 .
Therefore, it is possible to control the motion of each joint based on the detection of these

angle sensors

35 and 36, and to arbitrarily control the position, motion, and motion speed of the tool 104. FIG. Then, the driving device 1 for each joint 103 of the robot 100 outputs torque of the output shaft 32b at each joint 103 based on the sensor outputs of the high-speed shaft rotation angle sensor 35 and the low-speed shaft rotation angle sensor 36 used for motion control. can be controlled.
For this reason, by appropriately controlling the output torque individually by the driving device 1 in each joint 103, for example, the tool 104 of the robot 100 can press the workpiece W shown in FIG. It is possible to perform haptic control such as performing other work with the tool 104 while making contact or contacting with a certain pressing force (target value).

In the case of the robot 100, in order to perform force control, in order to link the motors 20 of the driving devices 1 in the joints 103, instead of the configuration provided in the control device 40 for each driving device 1, A configuration may be adopted in which a control device for integrally controlling each driving device 1 is provided. Alternatively, the configuration may be such that a high-level control device for linking the control devices 40 of the drive devices 1 is provided.
Further, the joints 103 of the robot 100 are not limited to the driving device 1 described above, and

other driving devices

1A and 1B may be provided.

[others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.
For example, in the above embodiment, the rotor magnet 21c of the motor 20A and the inner pole magnet 31a of the magnetic modulation gear device 30 form magnetic poles independent of each other. However, the field poles of the motor 20A and the magnetic poles of the high-speed rotor 31 of the magnetic modulation gear device 30 may be shared.

Further, in each of the

driving devices

1, 1A, 1B, both the high-speed shaft rotation angle sensor 35 and the low-speed shaft rotation angle sensor 36 are arranged in the casings 34, 34A. and the low-speed shaft rotation angle sensor 36 may be arranged in the

casings

34, 34A. Even in that case, any one of the

sensors

35 or 36 arranged inside is protected, and it is possible to improve the stability of detection and the reliability of the device.

Also, although the

motors

20 and 20A are illustrated as brushless motors, their types and structures are not particularly limited, and they may be, for example, synchronous machines or induction machines.
Further, in the magnetic modulation gear device 30 of each of the above-described embodiments, the outer pole magnet 33 is used as the stator, and the output is taken out from the low-speed rotor 32 having the magnetic pole pieces 32a. 33 may be connected to a rotatable low speed rotor and output may be extracted from the low speed rotor.

Further, in each of the above-described embodiments, the case where the magnetic modulation gear device 30 as a transmission is a speed reducer was illustrated, but the magnetic modulation gear device 30 as a transmission may be a speed increaser.
In that case, it can be realized by appropriately changing the number of pole pairs of the outer pole magnets 33, the number of pole pairs of the inner pole magnets 31a, and the number of magnetic poles of the magnetic pole pieces 32a.
Alternatively, the torque of the motor 20 may be input from the output shaft 32b side and high-speed rotation may be extracted from the shaft 23 side. In this case, the output torque on the shaft 23 side can be detected or controlled by obtaining the phase difference on the shaft 23 side.

Further, in the drive device 1B, the control device 40B has a function as a torque estimator (the phase difference calculator 42 and the torque acquirer 41B) and a function of controlling the input torque of the motor 20A. The two functions may be configured to be executed by separate controllers.
In that case, the magnetic modulation gear device 30 (or the magnetic modulation gear device 30 integrated with the motor 20A) is provided with a control element such as a chip that performs the function as the torque estimator, and the magnetic modulation gear device 30 alone outputs Torque may be detectable.

In addition, the details shown in the above embodiments can be changed as appropriate without departing from the spirit of the invention.

The present invention has industrial applicability for magnetic modulation gear devices, driving devices and robots.

1, 1A,

1B drive device

20, 20A motor (driving source)
23 shaft (input shaft)
30 magnetic

modulation gear device

31, 31A high-speed rotor 31a inner pole magnet 31b rotor yoke 32 low-speed rotor 32a magnetic pole piece (pole piece)
32b output shaft 33 outer pole magnet

33a yoke portions

34, 34A casing 35 high speed shaft rotation angle sensor (input shaft side sensor)
36 Low-speed shaft rotation angle sensor (output shaft side sensor)
37

Temperature sensor

40, 40B Control device 41 Phase difference output unit 41B Torque acquisition unit 42 Phase

difference calculation unit

43, 43B Subtractor 100 Robot 103 Joint Ax Central axis T ^* Torque command T_fb Output torque T_cmd Output torque deviation θ ^* Phase difference θ_fb Phase difference θ_cmdθ Deviation

Claims

In a magnetic modulation gear device having an input shaft and an output shaft that is output after being speed-changed with respect to the input shaft through a reduction section,
an input shaft side sensor that measures the rotation angle of the input shaft side;
and an output shaft side sensor that measures the rotation angle of the output shaft side.
with a housing,
2. The magnetic modulation gear device according to claim 1, wherein at least the input shaft side sensor or the output shaft side sensor is provided in the housing.
3. The magnetic modulation gear device according to claim 2, wherein both the input shaft side sensor and the output shaft side sensor are provided within the same space of the housing.
4. The torque estimator according to any one of claims 1 to 3, further comprising a torque estimator for estimating the output torque of the output shaft from the rotation angle measured by the input shaft side sensor and the rotation angle measured by the output shaft side sensor. Magnetic modulation gear device.
The magnetic modulation gear device according to claim 4, wherein the torque estimator corrects and estimates the output torque of the output shaft according to the temperature of the magnet of the magnetic modulation gear device.
a magnetic modulation gear device according to claim 4 or 5;
a drive source that applies an input torque to the input shaft;
and a control device that controls the input torque of the drive source from the difference between the output torque estimated by the torque estimator and the target output torque.
a magnetic modulation gear device according to any one of claims 1 to 3;
a drive source that applies an input torque to the input shaft;
a control device for controlling an operation amount of the drive source so that a target output torque is output from the output shaft based on the measured rotation angle of the input shaft and the measured rotation angle of the output shaft; A drive device comprising:
The driving device according to claim 7, wherein the control device corrects the operation amount of the driving source for outputting the target output torque according to the temperature of the magnet of the magnetic modulation gear device.
A robot having the driving device according to any one of claims 6 to 8.